摘要:

AbstractA new boundary element technique based on Green's formula is applied to the analysis of nonlinear water wave problems. The problems are formulated mathematically as two‐dimensional nonlinear initial‐boundary value problems in terms of a velocity potential, assuming the fluid to be inviscid and incompressible, and the flow to be irrotational.In the present paper, two kinds of wave‐making problems are analysed: (1) a tsunami generated by sea bed elevation; (2) generation, propagation and run‐up on a vertical wall of a solitary wave. Numerical results obtained by the present method are compared with available experimental data and analytical solutions. Excellent agreements are o

ISSN:0029-5981    

DOI:10.1002/nme.1620190702

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractFinite element models for linear elastic plane stress problems which provide, alternatively, a completely compatible displacement field or a precisely equilibrated stress field are developed. The basis for both models is a biquintic interpolation polynomial representing Airy's stress function over a triangular region. The polynomial coefficients are modified and grouped to establish compatibility while retaining equilibrium within each element. Nodal kinematic parameters are selected and matched to the stress function for the compatible (modified stiffness) model, while nodal stress function parameters are chosen for the equilibrium (modified flexibility) model. Constraints on the global freedoms, enforced by Lagrange multipliers, are introduced to augment nodal connectivity in establishing interelement compatibility in the ‘stiffness’ model and uniform stress transmission in the ‘flexibility’ model. Appropriate boundary conditions are formed for each model. Numerical solutions are obtained and a

ISSN:0029-5981    

DOI:10.1002/nme.1620190703

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractIn Reference 1 a series of general formulae for evaluating the total number of non‐zero blocks in the stiffness matrix, both of two‐dimensional and three‐dimensional (arbitrary polygonal/polyhedral) finite element networks, was presented. In this paper, an alternative, more direct and efficient method for deriving such formulae is presented. In addition, this new method can be used for more complex situations. In fact, it may be used for almost all kinds of finite element net

ISSN:0029-5981    

DOI:10.1002/nme.1620190704

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThis paper describes a new contouring algorithm for isoparametric elements which can be used to map three‐dimensional scalar fields. The contours are generated on arbitrary planes intersecting finite element structures. Tracing element contour lines is accomplished by an accurate predictor‐corrector technique. A method of finding starting points for the algorithm on the boundary of the elements is also gi

ISSN:0029-5981    

DOI:10.1002/nme.1620190705

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA technique is developed for the numerical analysis of wave motion in layered strata. Semidiscrete particular solutions satisfying inhomogeneous boundary conditions are calculated by the finite element method. These solutions are combined with semidiscrete modes of an appropriate eigenvalue problem. The boundary conditions corresponding to rigid and rough footings on a layered stratum are treated in detail. Applications are considered which demonstrate the validity of the technique.

ISSN:0029-5981    

DOI:10.1002/nme.1620190706

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe nonlinear diffusion equation as applied to two‐dimensional time‐dependent magnetic fields is solved with a finite element algorithm. This algorithm permits the analysis of problems possessing complex geometries, induced eddy currents, permanent magnets, and nonperiodic excitation currents. The numerical procedure utilizes implicit time stepping with an iterative scheme to solve the resulting set of equations. Two examples of applications of this program are presen

ISSN:0029-5981    

DOI:10.1002/nme.1620190707

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractAn improved bisection strategy is presented to determine the eigenvalues of a real symmetric tridiagonal matrix which occurs in a simple column buckling problem. The new strategy, which involves only a minor modification, utilizes incomplete Sturm sequences only as long as relevant information on the next and following eigenvalues is obtained resulting in a minimization of the computational work. The strategy is particularly effective if only a few eigenvalues are required. The technique can be used for a wider class of eigenvalue problems than the illustrative one presented here.

ISSN:0029-5981    

DOI:10.1002/nme.1620190708

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe problem of quasi‐stationary nonlinear magnetic fields is formulated in a variational form. A Galerkin finite element solution is constructed. Discretization in time is carried out by means of one‐ and two‐step linearA‐stable schemes. The resulting system of nonlinear equations is solved by Newton's method. A numerical example i

ISSN:0029-5981    

DOI:10.1002/nme.1620190709

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractEarlier formulations of the finite element approach to cylindrical (rz) field problems led initially to variational expressions containing a simple term in 1/rand consequent attempts to remove it by appropriate choice of interpolation functions. The present paper uses new interpolation functions which ensure that the field behaviour near the axis is correctly modelled. High‐order finite elements up to order four are derived and tested on a special cylindrical geometry to confirm, in a practical case, the theoretical claims of improved rates of convergence in solving problems of engineering significanc

ISSN:0029-5981    

DOI:10.1002/nme.1620190710

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620190711

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY